Selection and validation of reference genes for quantitative Real-time PCR analysis in Amana edulis / 中国中药杂志

Amana edulis is a traditional Chinese medicinal plant with low propagation coefficient. In recent years, the increasing demands of A. edulis lead to a shortage of its wild resources. In order to analyze the expression of related functional genes in A. edulis, the selection of suitable internal reference genes is crucial to improve the accuracy of experimental results. Eight genes(ACT, TUA, CYP, GAPDH, UBQ, UBI, EF1a, UBC)were chosen as candidate reference genes based on the RNA-Seq. Real-time fluorescence quantitative technique was used to detect the expression level of candidate internal reference genes in different organs(bulb, leaf, flo-wer) and stolons at different development stages of A. edulis. Then GeNorm, NormFinder, BestKeeper softwares and RefFinder website were used for a comprehensive analysis of the expression stability of the candidate genes.The results showed that among the 8 candidate reference genes, the variation range of Ct value of UBC was the smallest, and the expression level was stable, which was suitable for an reference gene. GeNorm and NormFinder software analysis showed that UBC and UBI were the optimal reference genes. BestKeeper analysis showed that CYP and UBC expression were relatively stable. Comprehensive evaluation of RefFinder website showed that UBC and UBI were the most stable genes, and ACT displayed the lowest stability in all software evaluation, indicating UBC and UBI were suitable for reference genes. Additionally, the most stable UBC, UBI and the most unstable ACT were used as internal reference genes to detect the expression of GBSS gene in A. edulis, and expression pattern of GBSS gene was the same under the calibration of UBC and UBI. The expression data of GBSS gene confirmed that UBC and UBI genes were reliable for A. edulis qRT-PCR as internal reference genes. The results would benefit future studies on related gene expression of A. edulis.

Selection of suitable reference genes for abiotic stress-responsive gene expression studies in peanut by real-time quantitative PCR

Background: Because of its strong specificity and high accuracy, real-time quantitative PCR (RT-qPCR) has been a widely used method to study the expression of genes responsive to stress. It is crucial to have a suitable set of reference genes to normalize target gene expression in peanut under different conditions using RT-qPCR. In this study, 11 candidate reference genes were selected and examined under abiotic stresses (drought, salt, heavy metal, and low temperature) and hormone (SA and ABA) conditions as well as across different organ types. Three statistical algorithms (geNorm, NormFinder and BestKeeper) were used to evaluate the expression stabilities of reference genes, and the comprehensive rankings of gene stability were generated. Results: The results indicated that ELF1B and YLS8 were the most stable reference genes under PEG-simulated drought treatment. For high-salt treatment using NaCl, YLS8 and GAPDH were the most stable genes. Under CdCl2 treatment, UBI1 and YLS8 were suitable as stable reference genes. UBI1, ADH3, and ACTIN11 were sufficient for gene expression normalization in low-temperature experiment. All the 11 candidate reference genes showed relatively high stability under hormone treatments. For organs subset, UBI1, GAPDH, and ELF1B showed the maximum stability. UBI1 and ADH3 were the top two genes that could be used reliably in all the stress conditions assessed. Furthermore, the necessity of the reference genes screened was further confirmed by the expression pattern of AnnAhs. Conclusions: The results perfect the selection of stable reference genes for future gene expression studies in peanut and provide a list of reference genes that may be used in the future.

Cloning and expression stability analysis of actin gene in Eleutherococcus senticosus / 中草药

Objective: To clone the actin (ACT) gene of Eleutherococcus senticosus, and to make the gene a valuable internal gene. Methods: Part of the sequence of ACT gene was cloned by real-time PCR (RT-PCR), and the sequence was used as internal control gene for analyses of semiquantitative PCR and RT-PCR. Results: The ACT gene (1031 bp) of E. senticosus was cloned, coding 343 amino acids. To compare the amino acid sequence of E. senticosus ACT gene with those of Betula luminifera, Gossypium hirsutum, and Camellia sinensis, the amino acid homology was 99.42%, 98.83%, and 98.54%. The expression of ACT in different organs of E. senticosus during various growing periods was constant. The expression of ACT gene in different organs and during different growth and development stages was basically constant, and when the sequence acted as internal control gene, the semiquantative PCR and RT-PCR have good amplification effect and reproducibility. Conclusion: The ACT sequence in E. senticosus is firstly separated and reported, it could act as an internal control gene, and its reaction system of RT-PCR is established.

Comparison of Recombinant Human ?-NGF from E.coli and CHO in Biochemical Characters / 中国生物工程杂志

Though prokaryotic cells could hardly express recombinant human beta nerve growth factor (rhNGF-?) with a proper three-dimensional conformation, using of E. coli as a host for industrial production of rhNGF-? is controversial. Recombinant human beta NGF was expressed in E. coli and was refolded in vitro. The isolated products was shown to be consistent with those expressed and secreted by CHO cells in biochemical characters by SDS-PAGE, RP-HPLC, mass spectrometry, N terminal analysis and bioassay determined using DRG and PC12 cells. The products can be acquired with 95% purity, 1.8 ng/U biological activity from both expression system,which remain invariable biological activity when lyophilized in excipient and store at 37℃?2℃, RH 75%?5% for 3 months. Moreover, the product refolded from inclusion bodies of E. coli shows the predominance in homogeneity and the lower cost.